CN201000802Y - Transformer capable of adjusting mutual inductance - Google Patents

Abstract

A transformer capable of adjusting mutual inductance comprises a main iron core, two coils surrounding the main iron core and an adjusting iron core. The coils have a mutual inductance effect between them. The sectional area of the adjusting iron core is smaller than that of the main iron core, the adjusting iron core is arranged between the coils and is adjacent to the main iron core, and the adjusting iron core can move relative to the main iron core. Therefore, the mutual inductance between two adjacent coils can be adjusted by utilizing the movement of the adjusting iron core relative to the main iron core, the excitation magnetic flux of the coils, which is influenced by the mutual inductance effect, is improved, and the purpose of enabling the current on the coils to obtain average and stable use is further achieved.

Description

Transformer with adjustable mutual inductance

technical field

The utility model relates to a transformer, in particular to a transformer with adjustable mutual inductance.

Background technique

At present, most liquid crystal displays need cold cathode fluorescent tubes (Cold Cathode Fluorescent Lamp, CCFL) as the main light source, because lighting such lamps must use high voltage, so the commutation circuit composed of inverters will be used to achieve lighting. Action, the commutation circuit uses a converter transformer as a booster component, which can be divided into a one-to-one method in which one converter transformer drives one lamp tube, and a one-to-many method in which one converter transformer drives two lamp tubes. Taking a 32-inch liquid crystal display as an example, 16 lamp tubes must be used to provide the backlight at present. As the number of lamps increases, the number of lamp tubes required also increases. It is conceivable that the number of converter transformers will also increase. In order to reduce the number of converter transformers and save costs, the use of one-to-many lighting in the future will become major trends.

As shown in Figure 1, it is the current one-to-many transformer form, the transformer 200 includes two winding shafts 20 and two U-shaped iron cores 21 combined with the winding shafts 20, one of the winding shafts 20 combined On one side of the U-shaped iron core 21, a primary coil 201 is wound, and the other is combined on the other side of the U-shaped iron core 21 corresponding to the former, and two secondary coils 202 are wound around the primary coil 201. The coupling effect is generated simultaneously with the secondary coil 202, and the two ends of the secondary coil 202 can be respectively connected to a lamp tube (as shown in FIG. 2 ), however, the distance between the secondary coil 202 is still quite close, It is unavoidable that there is mutual inductance between the two secondary coils 202. If the coupling K between the two secondary coils 202 and the primary coil 201 is very high, the equivalent circuit is as shown in FIG. 3 and further converted into FIG. 4 It means that the actual output situation will be equivalent to a way of connecting a group of parallel loads in series with two output terminals, that is, the output current (I) is equal to the sum of the two load currents (I1+I2 and I3+I4) (I=I1+ I2=I3+I4), and because the impedance of each lamp tube is different, the shunt effect makes the current flowing through each lamp tube different, and the mutual inductance effect of the secondary coil 202 is affected, so that the two output voltages generate mutual If cancellation or amplification occurs, the disadvantage of the first form will also occur, that is, the load current of individual lamps cannot be equalized to maintain a stable brightness. Based on the above-mentioned prior art, it can be known that the primary coils 101, 201 and The coupling K of the secondary coils 102, 202 should not be too high, otherwise the output will be equivalent to a parallel load, so the average effect of the output current of the secondary coils 102, 202 will be poor, but if the coupling K is reduced, then The leakage current of the secondary coils 102 and 202 will increase again, which will cause the secondary coils 102 and 202 to be unable to effectively supply power to the lamp tube, so in fact, it is enough to provide an appropriate coupling K.

Contents of the invention

The purpose of the utility model is to provide an adjustable mutual inductance transformer that can effectively adjust the mutual inductance effect of two adjacent coils, and then make the current on each induction coil average and stable.

The transformer with adjustable mutual inductance includes a main iron core and two coils surrounding the main iron core, and the coils have a mutual inductance effect.

The utility model is characterized in that: the transformer also includes an adjusting iron core whose cross-sectional area is smaller than the main iron core, and the adjusting iron core can be moved relative to the main iron core and is arranged between the coils and adjacent to the main iron core.

The effect of the utility model is that the mutual inductance between two adjacent coils can be adjusted by utilizing the movement of the adjusting iron core relative to the main iron core, the excitation magnetic flux of the coils interacting with each other due to the mutual inductance effect can be improved, and the effective magnetic circuit length can be increased. Therefore, the main magnetic circuit of the transformer has loose coupling and close coupling functions at the same time, so that the current on the coil can be averaged and stable.

Description of drawings

Fig. 1 is a schematic diagram illustrating the form of a conventional transformer;

Fig. 2 is a schematic diagram illustrating the situation in which two secondary coils generate mutual inductance and are mutually coupled with a primary coil in the above-mentioned transformer;

Fig. 3 is a schematic diagram illustrating the equivalent circuit of the above-mentioned transformer when the coupling of the secondary coil is relatively high;

Fig. 4 is a schematic diagram illustrating that in the above-mentioned transformer, two sets of lamp tubes are equivalent to a parallel load;

Fig. 5 is a schematic diagram illustrating the first preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 6 is a three-dimensional exploded view illustrating that in the above-mentioned first preferred embodiment, the cross-sectional area of an adjusting iron core is not greater than the effective cross-sectional area of a main iron core;

Fig. 7 and Fig. 8 are a schematic diagram illustrating the second preferred embodiment of the utility model adjustable mutual inductance transformer;

Fig. 9 and Fig. 10 are a schematic diagram illustrating the third preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 11 is a schematic diagram illustrating the fourth preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 12 and Fig. 13 are a schematic diagram illustrating the fifth preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 14 is a schematic diagram illustrating the sixth preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 15 is a schematic diagram illustrating the seventh preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 16 is a schematic diagram illustrating the eighth preferred embodiment of the transformer with adjustable mutual inductance of the present invention;

Fig. 17 is a schematic diagram illustrating the ninth preferred embodiment of the transformer with adjustable mutual inductance of the present invention; and

FIG. 18 and FIG. 19 are schematic diagrams illustrating the tenth preferred embodiment of the transformer with adjustable mutual inductance of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

Before the present utility model is described in detail, it should be noted that in the following description, similar components are denoted by the same numerals.

As shown in Figures 5 and 6, the first preferred embodiment of the utility model adjustable mutual inductance transformer includes two adjacent coils 60 with mutual inductance effect, a main core 61 surrounded by the coils 60, a cross-sectional area smaller than The adjusting iron core 62 of the main iron core 61 and a frame body 63 straddling the two sides of the main iron core 61 and allowing the adjusting iron core 62 to pass through, the frame body 63 is n-shaped in the first preferred embodiment.

The main core 61 is composed of two U-shaped cores 610 (UU type), and one side is wound into two primary coils 611, and the opposite side is wound into two secondary coils 612. The main core 61 includes A remote portion 614 away from the adjusting iron core 62 , the cross-sectional area of the remote portion 614 is larger than the effective cross-sectional area 613 of the main iron core 61 .

The coil 60 refers to the secondary coil 612 in this first preferred embodiment, and may also be the primary coil 611 during actual manufacture, and the primary coil 611 in this first preferred embodiment is based on The same wire is directly connected in series, and it can also be connected in series through an external circuit formed on a circuit board during actual manufacturing.

The cross-sectional area 621 of the adjusting iron core 62 is not larger than the effective cross-sectional area 613 of the main iron core 61, and the adjusting iron core 62 is arranged between the coils 60 and close to the main iron core 61. In the first preferred embodiment, the The adjusting iron core 62 straddles two sides of the main iron core 61 and both ends contact the main iron core 61 , thus forming a contact area 622 .

The adjustment core 62 can move forward or backward in the frame body 63 along a long direction X, while generating mutual inductive magnetic flux without dividing the coil 60, and making the exciting magnetic flux substantially not form an effective magnetic flux. Under the condition of shunting, by changing the relative position between the adjustment iron core 62 and the main iron core 61, the size of the contact area 622 between the adjustment iron core 62 and the main iron core 61 can be changed, thereby affecting the inductance of each coil 60 The mutual inductance effect of the quantity change is reduced, and finally the adjustment iron core 62 and the main iron core 61 are fixed by dispensing glue, and the operation of adjusting the mutual inductance effect of the transformer can be completed.

The above-mentioned operation of adjusting the mutual inductance between two adjacent coils 60 by using the adjusting iron core 62 is based on the principle of the following formula, so the exciting magnetic flux of the coil 60 can be improved because of the interaction of the mutual inductance effect:

When performing the adjustment operation, by appropriately increasing the effective magnetic circuit length, the main magnetic circuit of the transformer can have loose coupling and close coupling functions at the same time, and then the current on the coil 60 can be averaged and stabilized. Purpose.

In addition, it is worth mentioning that since the cross-sectional area of the remote portion 614 of the main core 61 is greater than the effective cross-sectional area 613 of the main core 61, the coupling effect of the secondary coil 612 on the part adjacent to the primary coil 611 will be The part of the secondary coil 612 adjacent to the adjustment core 62 will form a loose coupling, so that the traveling wave entering from the remote part can be reduced to avoid the formation of a standing wave.

As shown in Figures 7 and 8, the second preferred embodiment of the present utility model will be further described below. The relative displacement between the main iron cores 61 changes the air gap distance 623 (vertical air gap) between the adjustment iron core 62 and the main iron core 61 by means of vertical movement. For example, as shown in FIG. An insulating spacer 64 is set in the middle, so that the spacer 64 is between the main iron core 61 and the adjustment iron core 62, then when the adjustment iron core 62 is set on the frame body 63, it can be obtained through the spacer 64 For the air gap distance 623 of different vertical heights, the effect of adjusting the air gap distance 623 can be achieved by using gaskets 64 of different thickness specifications in accordance with the actual situation. In addition, as shown in Figure 8, an eccentric rotating the rotating wheel 65, so that the rotating wheel 65 abuts against the bottom of the adjusting iron core 62, so that the effect of adjusting the air gap distance 623 can be achieved by rotating the rotating wheel 65, and the adjustment of the coil can also be achieved. The purpose of using the mutual inductance between 60.

As shown in Figures 9 and 10, the third preferred embodiment of the present utility model will be further described below. The third preferred embodiment is substantially the same as the second preferred embodiment above. The relative displacement between the main iron cores 61 is to change the air gap contact area 624 between the adjustment iron core 62 and the main iron core 61 by making the adjustment iron core 62 advance or retreat along the long direction X (such as The area projected downward as shown in FIG. 9 ), in addition, the air gap distance 623 can also be changed by adjusting the iron core 62 to move horizontally along the long direction X (forming a horizontal air gap as shown in FIG. 10 ), then the same The purpose of adjusting the mutual inductance between the coils 60 can be achieved. It is worth mentioning that the coils 60 shown in FIGS. 9 and 10 are connected in series through the external circuit 70 formed on a circuit board.

As shown in Figure 11, the fourth preferred embodiment of the present utility model will be further described below. The fourth preferred embodiment is substantially the same as the above-mentioned first preferred embodiment, except that the two sides of the main core 61 are respectively A primary coil 611 and a secondary coil 612 are wound around, the coil 60 refers to the secondary coil 612 in the fourth preferred embodiment, and may also refer to the primary coil 611 in practical application, wherein in In the fourth preferred embodiment, as long as the adjusting iron core 62 and the main iron core 61 are used to move relative to each other, the adjustment of the coil 60 can also be adjusted by the adjustment methods of the first, second, and third preferred embodiments. The effect of using mutual inductance.

As shown in Figures 12 and 13, the fifth preferred embodiment of the present invention will be further described below, which is roughly the same as the first preferred embodiment above, except that the primary coil 611 and The secondary coils 612 are all wound on the same side of the main core 61, wherein the primary coils 611 shown in FIG. 12 are wound on opposite ends of the secondary coils 612 and directly connected in series, and the The coil 60 refers to the secondary coil 612, and the secondary coil 612 shown in FIG. In succession, the adjustment iron core 62 is arranged between the coils 60, and straddles the two sides of the main iron core 61, as long as the adjustment iron core 62 and the main iron core 61 are used to move relative to each other, by the above-mentioned first The adjustment methods in preferred embodiments 1, 2, and 3 can also achieve the effect of adjusting the mutual inductance between the coils 60 .

As shown in Figure 14, the sixth preferred embodiment of the present utility model will be further described below. The adjusting iron core 62 of the sixth preferred embodiment is arranged in the middle of a bobbin frame 66, and the two sides of the bobbin frame 66 are wound A primary coil and a secondary coil are provided, and a plurality of bumps 661 that can be pressed against the side of the adjustment iron core 62 are arranged in the middle. The adjustment iron core 62 is kept fixed by the push of the protrusions 661, and can Pushed by external force to achieve the function of adjusting the mutual inductance effect between the coils on both sides.

As shown in Figure 15, the seventh preferred embodiment of the present utility model will be further described below. The seventh preferred embodiment is substantially the same as the sixth preferred embodiment above, except that a One side of the opening is provided with a shrapnel 662 to provide resistance, and the other side of the opening is provided with a bolt 663. The adjusting iron core 62 is sandwiched between the shrapnel 662 and the bolt 663. When the bolt 663 rotates, it can move The adjusting iron core 62 moves up and down with the shrapnel 662 as a fulcrum at an elevation angle, thereby changing the length of the vertical air gap between the adjusting iron core 62 and the main iron core 61 to achieve the function of adjusting the mutual inductance effect between the coils on both sides.

As shown in Figure 16, the eighth preferred embodiment of the present utility model will be further described below. On the opening side, there is a bolt 663 against the adjusting iron core 62. The radial width of the bolt 663 is different, so when the bolt 663 rotates, it can push the adjusting iron core 62 to slide back and forth, and adjust the two sides. A function of the mutual inductance effect between the coils.

As shown in Figure 17, the ninth preferred embodiment of the present invention will be further described below. The ninth preferred embodiment is substantially the same as the sixth preferred embodiment above. The long bolts arranged in the middle of the bobbin 66 can adjust the air gap area between the main core 61 and the main core 61 by screwing in and out, thereby achieving the function of adjusting the mutual inductance effect between the coils on both sides.

As shown in Figures 18 and 19, the tenth preferred embodiment of the present invention will be further described below. The tenth preferred embodiment is roughly the same as the above-mentioned first preferred embodiment, except that it also includes a primary winding frame 81 , a secondary winding frame 82 , and a connecting frame 83 connected to the primary winding frame 81 and the secondary winding frame 82 .

The connecting frame 83 includes a first frame body 831 combined with the primary winding frame 81, a second frame body 832 combined with the secondary winding frame 82, and a plurality of frames respectively formed on the first and second frame bodies. 831, 832 and the connecting piece 833 that can be combined with each other, and a penetrating space 834 that extends from the first frame body 831 to the second frame body 832 and can accommodate the adjusting iron core 62, and the connecting piece 833 is respectively The connection is formed with a concave-convex block structure.

The main iron core 61 is passed through the primary winding frame 81 and the secondary winding frame 82, the aforementioned coil (not shown) having a mutual inductance effect is wound on the secondary winding frame 82, and the adjusting iron core 62 is passed through In the penetrating space 834 of the connecting frame 83 , it can be pushed along the penetrating space 834 by an external force, thereby producing the function of adjusting the mutual inductance effect.

Therefore, it can be known from the descriptions of the above-mentioned preferred embodiments that no matter whether the aforementioned coil with mutual inductance refers to the primary coil or the secondary coil, the utility model can adjust the displacement of the iron core 62 relative to the main iron core 61, so that The mutual inductance between the coils is adjusted, so as to achieve the purpose of making the current on the coils average and stable.

Claims (22)

1. A transformer with adjustable mutual inductance, comprising a main iron core, and two coils surrounding the main iron core, with a mutual inductance effect between the coils, characterized in that: The transformer also includes an adjusting iron core whose cross-sectional area is smaller than that of the main iron core. The adjusting iron core is movably arranged between the coils relative to the main iron core and adjacent to the main iron core. 2. The transformer with adjustable mutual inductance according to claim 1, characterized in that: the cross-sectional area of the adjusting iron core is not larger than the effective cross-sectional area of the main iron core. 3. The transformer with adjustable mutual inductance according to claim 1, characterized in that: said main core includes a remote part away from said adjusting core, and the cross-sectional area of said remote part is larger than the effective cross-sectional area of said main core area. 4. The transformer with adjustable mutual inductance according to claim 1, wherein the coils are directly connected in series. 5. The transformer with adjustable mutual inductance according to claim 1, characterized in that: said coils are connected in series via external lines. 6. The transformer with adjustable mutual inductance according to claim 1, characterized in that: one side of the main core is wound as a primary coil, and the opposite side is wound as a secondary coil, and the coil is wound The primary coil on the main iron core, the adjustment iron core straddles the two sides of the main iron core. 7. The transformer with adjustable mutual inductance according to claim 1, characterized in that: one side of the main core is wound as a primary coil, and the opposite side is wound as a secondary coil, and the coil is wound The secondary coil on the main iron core, the adjustment iron core straddles the two sides of the main iron core. 8. The transformer with adjustable mutual inductance according to claim 1, characterized in that: one side of the main core is wound as a primary coil, and the same side is also wound as a secondary coil, and the coil is wound on The primary coil on the main core, the adjusting core is arranged between the primary coils and straddles the two sides of the main core. 9. The transformer with adjustable mutual inductance according to claim 1, characterized in that: a primary coil and a secondary coil are respectively wound on both sides of the main core, and the coil is wound on the main core The secondary coils, the adjusting iron core is arranged between the secondary coils and straddles the main iron core. 10. The transformer with adjustable mutual inductance according to claim 1, characterized in that two primary coils are wound on one side of the main core, and a secondary coil is wound on the same side at opposite ends of the primary coil. A secondary coil, the coil is a secondary coil wound on the main core, the primary coils are directly connected in series, the adjustment core is arranged between the secondary coils, and straddles the main coil Both sides of the core. 11. The transformer with adjustable mutual inductance according to claim 1, characterized in that two secondary coils are wound on one side of the main core, and two secondary coils are wound on the same side at opposite ends of the secondary coils. A primary coil, the coil is a primary coil wound on the main iron core and directly connected in series, the adjustment iron core is arranged between the secondary coils and straddles the two sides of the main iron core. 12. The transformer with adjustable mutual inductance according to claim 1, characterized in that: the adjustment core includes a contact area with the main core, and the adjustment core can move relative to the main core to change the the contact area. 13. The transformer with adjustable mutual inductance according to claim 1, characterized in that: said adjusting iron core includes an air gap extending to said main iron core, and said adjusting iron core can be moved relative to said main iron core to change The air gap distance. 14. The transformer with adjustable mutual inductance according to claim 1, characterized in that: said adjusting iron core includes an air gap contact area adjacent to said main iron core, and said adjusting iron core can move relative to said main iron core And change the air gap contact area. 15 . The transformer with adjustable mutual inductance according to claim 1 , further comprising a frame straddling the two sides of the main iron core and allowing the adjustment iron core to pass through. 16 . The transformer with adjustable mutual inductance according to claim 1 , further comprising an insulated spacer disposed between the main iron core and the adjustment iron core. 17. The transformer with adjustable mutual inductance according to claim 1, characterized in that it further comprises a frame straddling both sides of the main iron core, and a runner arranged on the frame and rotating eccentrically, The running wheel abuts against the bottom of the adjusting iron core. 18. The transformer with adjustable mutual inductance according to claim 1, characterized in that it also comprises a bobbin for winding the coil, the adjusting iron core is arranged in the middle of the bobbin, the The bobbin includes a plurality of bumps that can abut against the side of the adjusting iron core. 19. The transformer with adjustable mutual inductance according to claim 1, characterized in that: it also comprises a winding frame for winding the coil, an elastic piece arranged on an opening side of the winding frame, and A bolt is arranged on the other opening side of the winding frame, and the adjusting iron core is sandwiched between the elastic piece and the bolt. 20. The transformer with adjustable mutual inductance according to claim 1, characterized in that it further comprises a bobbin on which the coil can be wound, and the adjusting iron core is a winding frame that passes through the middle of the bobbin long bolts. 21. The transformer with adjustable mutual inductance according to claim 1, characterized in that it further comprises a primary winding frame, a secondary winding frame, and a The connecting frame of the wire frame, the main core is passed through the primary winding frame and the secondary winding frame, and the coil is wound between the primary winding frame and the secondary winding frame One, the adjusting iron core is passed through the connecting frame. 22. The transformer with adjustable mutual inductance according to claim 21, characterized in that: said connecting frame comprises a first frame body combined with said primary winding frame, a first frame body combined with said secondary winding frame The second frame body, a plurality of joints formed on the first and second frame bodies respectively and can be combined with each other, and one extending from the first frame body to the second frame body and can accommodate the Describe the space for adjusting the penetration of the iron core.

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